The paper presents the authors’ concept of an adaptive road lighting that is concurrent with vehicles moving on roads. The lighting system is based on luminaires with light emitting diodes. The authors describe the operation of the adaptive road lighting system and point out benefits and limitations of the solution. The theoretical considerations are supported by an analysis of the installed and working system that was implemented at Bożeny street in Poznan, Poland. The system was also evaluated by the residents living near the street.

The article proposes a method for measuring discomfort glare which uses numerical description of the phenomenon in the form of a digital luminance distribution map recorded on a CCD array. Essential procedures for determining partial quantities which are necessary for calculation of UGR index are discussed in detail, along with techniques for measuring position index and size of light sources, with regard to the parameters of the registering system and coordinates of the images of the sources on the array.

In 2020, an international project on residential lighting started and was implemented in four countries (Poland, Sweden, UK and Turkey). This article presents the results of a survey carried out in Poland, in the winter term between November 2020 and January 2021. A total of 125 Polish residents (59 women, 65 men, one person did not wish to specify gender) participated in the survey. A variety of data was collected on the respondents and their assessments as well as on their satisfaction with day- and artificial lighting in residential living spaces. The results from questionnaires were analyzed with STATISTICA 13.3. Descriptive statistics and Spearman rank order correlations were adopted to identify the light-related aspects, lighting patterns, and respondents’ perception of day- and artificial lighting conditions in living areas. The results revealed that satisfaction with daylighting in the living area, both in summer and winter, was significantly correlated with daylighting level, daylighting uniformity, sunlight exposure and view-out. The results also revealed that satisfaction with artificial lighting was significantly correlated with artificial lighting level, artificial lighting uniformity and color rendering. The results provide valuable information on lighting and factors that influence the luminous environment in residential living spaces.

Designing, optimizing and analyzing optical systems as part of the implementation process into production of modern luminaires require using advanced simulation and computational methods. The progressive miniaturization of LED (light emitting diode) chips and growth in maximum luminance values, achieving up to 108 cd/m2, require constructing very accurate geometries of reflector and lens systems producing complex luminous intensity distributions while reducing discomfort glare levels. Currently, the design process cannot function without advanced simulation methods. Today’s simulation methods in the lighting technology offer very good results as far as relatively large conventional light sources such as halogen lamps, metal halide lamps and high pressure sodium lamps are concerned. Unfortunately, they often fail in the case of chip-on-board LED light sources whose luminous surface dimensions are increasingly often contained inside a cube of the side length below 1mm. With the high sensitivity of such small chips and lenses with dimensions ranging from a just a few to between 10 and 20 mm, which is presented in this paper, modern luminance distribution measurement methods, luminance modelling and ray tracing methods should be used to minimize any errors arising from incorrectly projecting the design in the final physical model. Also, very importantly, focus should be directed towards reducing a chance of making a mistake while collimating the position of the light source inside the optical system. The paper presents a novel simulation calculation method enriched with an analysis of optical system sensitivity to a light source position. The results of simulation calculations are compared with the results of laboratory measurements for corresponding systems.

Lighting technologies developed significantly in the last decade. New LED light sources, dedicated luminaires and improved lighting control techniques gave rise to new possibilities in improving energy efficiency of lighting solutions. The article is an overview of interior, road and exterior architectural object lighting design strategies. It also presents design considerations that directly impact lighting conditions and energy efficiency. Practical examples of the application of basic design strategies, accompanied by the obtained energy results, are also depicted. Issues discussed in the article may be useful in researching and designing interior and road lighting, as well as floodlighting. They can also be useful in planning and implementing strategies aimed at improving lighting conditions and energy efficiency of lighting solutions.

Directionality of light and modelling effects impact lighting quality in interiors. The modelling effects depend on luminaires’ photometric characteristics and their layout but also on interior size and reflectance. The objective of this research was to evaluate lighting design limitations and impact of interior and luminaires’ characteristics on the modelling effects, as well as elaborate a prediction method of the modelling effects in interior lighting. The General Index of Modelling was used for the analysis of the modelling effects in interiors. The implementation of the research objectives was based on the simulation and statistical analysis. 432 situations, varied interior size and reflectance, lighting class, luminaire downward luminous intensity distribution and layout were considered. The results show that achieving the required range of the General Index of Modelling in interior lighting is substantially limited. Luminaires’ layout impacts the General Index of Modelling the most. The elaborated multiple linear regression models can have a practical use for interior lighting design and analysis in terms of obtaining therequired range of the General Index of Modelling.

The article presents how multi-layered urban lighting projects fit into the programs of integrated activities to improve the living conditions of the local community, the surrounding space, and its economic relations. The role of the electric lighting in revealing the night image of the city, its promotion and public spaces transformations offering new impressions to city residents is growing thanks to the use of the SSL technology. The authors focus on a role of outdoor lighting projects in urban regeneration within the selected urban areas. The paper describes how conscious shaping of lighting by analysing the goals and stages of the project can contribute to the improvement of quality in the processes of renewal of degraded urban areas.

General lighting is the most common way of illuminating interiors and the source of electricity consumption in buildings. This fact forces the search for lighting solutions effective both for people and the environment. In this study the impact of room and luminaire characteristics on general lighting conditions and energy efficiency in interiors is considered. In rooms of different sizes and reflectances, seventeen luminaire types with various light distributions were arranged in uniform layouts. The levels of average illuminance, uniformity and normalised power density related to two horizontal working planes were calculated. The impact of working plane reduction, room index and reflectances, lighting class and luminous intensity distribution of luminaire on the considered parameters was investigated. The use of the reduced working plane resulted in the increase in the average illuminance (7.7% on average), uniformity (33% on average) and normalised power density (23% on average). The impact of the room index and lighting class on the average illuminance and normalised power density was significant while the impact of the luminaire luminous intensity distribution and room reflectances was low. The normalised power density levels of the general electric lighting in interiors, with luminaire luminous efficacy of 100 lm/W, are in the following range: 1.08‒3.42 W/m² per 100 lx. Based on these results a normalised power density level of 2 W/m² per 100 lx is recommended for designing and assessing the new general electric lighting systems in buildings.

The β phase (Al ₁₂Mg ₁₇) precipitated by heat treatment in some alloy compositions may result deterioration of corrosion resistance. However, much of its role remains unclear. The effect of the β phase on the corrosion resistance behavior in a NaCl solution was presented in this study. The specimen was Mg-9mass%Al (AM90) alloy and the content of the β phase precipitant was controlled systematically by aging time at 473 K. Area rate of β and lamellar phase in the specimens were 0, 10 and 100%, respectively. According to the results of cathodic polarization curves measurement, the corrosion current density of α phase was 0.215 A/m2 and β phase of it was 0.096 A/m2. While, the specimen includes 10% of β and lamellar phase showed large corrosion current density of 0.251 A/m2. Positive correlation between the β phase and the open circuit potential, suggest that the β phase acts as a cathodic electrode. Moreover, the microstructure after postentiostatic corrosion tests was also support the role of β phase.

The paper puts forward and implements a method of designing and creating a modelling simulation environment for extensive and complete analysis of economical lighting on highways. From a general design viewpoint, the proposed solution explores the concept of a network description language (SMOL), which has been designed to describe the necessary network functions, mechanisms, and devices for the purpose of their computer simulation and verification. The presented results of the performed research confirm the usability of intelligent lighting on highways, both in the sense of the design concept and in the aspect of saving energy.

Lighting sources with a cold cathode are widely used in electronics. The lamps with a cold cathode are used primarily as sources of white light in optical scanners, digital indicators, display panels and signalling devices. In the paper the advantages of carbonaceous materials as emitters of cold electrons and the possibilities of using them to create a cathode in an electron lamp are discussed.

This work suggests a brand-new 1*4 two-dimensional demultiplexer design based on multicore photonic crystal fiber. Numerical models show that the optical signals can be separated in a photonic crystal fiber construction using optical signals with wavelengths of 0.85, 1.1, 1.19, and 1.35 μm injected on the center core and separated into four cores. The innovative design switches different air-hole positions using pure silica layers throughout the length of the fiber to regulate the direction of light transmission between layers.
Wavelength demultiplexers are essential parts of optical systemic communications. They serve as a data distributor and can use a single input to produce multiple outputs. The background material is frequently natural silica, and air holes can be found anywhere throughout the length of the fiber as the low-index components.
The simulation results showed that after a 6 mm light propagation, the four-channel demux can start to demultiplex.

The article has presented the method of 3D Digital Light Processing printing as one of the technologies used for rapid prototyping of dental models and making elements of dentures. In this work the research was presented, which the aim was to determine the effect of additional exposure time on the properties of the obtained printouts. Dynamic Mechanical Analysis test showed significant differences in stiffness between uncured specimens as well as specimens cured for 10, 20 and 30 minutes. In turn the obtained TG and DTG curves allowed to determine the most optimal curing time for DLP printouts. These studies provide the basis for determining the most appropriate method for handling printouts after the process of printing from liquid resin, so that they are the best possible quality for dentists and prosthodontists.

The development of technology and design of light management systems remains dynamic. Among all the benefits offered by these systems, the most valuable might definitely be the possibility of saving energy consumption. Knowing the value of energy savings is the key factor that users need to know before deciding to use a lighting management system (the type of light management system). For this purpose, it is useful to simulate the operation of the lighting control system, for example in the DIALux program. Such simulation helps evaluate potential savings in electricity consumption using the proposed lighting control system. In the DIALux program, it is possible to change the luminous flux value of luminaires. In such a case, it becomes possible to semi-simulate the light management system’s operation as we don’t receive actual information on reducing installed power of the lighting system during reduction of the luminous flux value of luminaires. This article shows what type of technical data are important to use for the DIALux program to properly and accurately simulate light management systems and to receive accurate data on energy saving. It also presents the results of photometrical and electric parameter measurements (Φ – luminous flux, P – power, PF – power factor, THDi – total harmonic distortion of current). The article discusses the power control characteristics obtained on the basis of these measurements and explores the source of differences between simulation of energy saving calculations and real measured energy savings. An existing lighting control system installed in an office reception area was used to compare calculations with the real value of energy consumption reduction. The impact of electronic power and control systems on electrical network parameters is also an important problem mentioned in this article. It also explores the effect of power regulation of LED luminaires and LED modules on the value of the power factor and total harmonic distortion (current) value (THDi).

Road lighting is a fundamental public service for the safety of pedestrians and drivers. Due to the global energy crisis and climate change, energy conservation has become a priority in any country. Road lighting should provide the required quality and quantity of illumination in the most efficient manner possible. In this work, a study of lighting conditions was carried out in an Argentinian city, and energy efficiency was evaluated based on three methods. The results and conclusions of the work provide an objective critique of the advantages and disadvantages of applying each method to measure the efficiency of an installation.

The research considers the aspect of the formation of interior lightning in conditions of extensive expenses on heating. In this regard there is important to study features not only of places and model of lightning, but also generation of heat in order to minimize expenses and find alternative technical solutions for building functioning. The relevance is determined by the fact that the problem of low efficiency of thermal energy used to ensure an appropriate microclimate in buildings is typical for many regions. The purpose of this article is to study features not only of places and model of lighting but also generation of heat to minimize expenses and find alternative technical solutions for building functioning. In the work, the methods of calculation methods and mathematical models such as the exergy model of humans were used. The authors have determined that daylight is only one of the complex solutions of the matter of building energy efficiency. Providing the conditions of heating comfort indoors is not less important in the conditions of increasing requirements to energy conservation. The authors consider the compromise between these two requirements without harming human health the main challenge to the energy conservation specialists. The authors have developed the model, which evaluates not only the achievements of technical parameters, but also orientation toward the model of energy consumption of human. The practical application of the developed methodology allows for forecasting not only building heating based on projected technical indicators but also tailored to individual needs.

In recent years, scattered light measurement technology has developed into a common method for measuring roughness, form and waviness on precision machined surfaces. Meanwhile, the application for the material structure evaluation of electrolytically anodized surfaces has also been considered. In this context,we present a novel approach to layer thickness measurement of naturally anodised aluminium surfaces. Our approach is based on the reflection intensity of the light beam, which penetrates the oxide layer and is reflected back from the surface as well as from the layer base. In the approach, a model for estimating reflection intensity I from the absorption coefficient is employed. The methodology is tested by comparing results to a layer thickness evaluation using metallographic preparation. Based on the proposed approach, we are able to measure intervals of layer thicknesses on naturally anodized aluminium surfaces without contact.

Lighting of the workplaces has a large impact on safety, proper vision comfort and visual efficiency. The aim of this article is to present an analysis of the lighting of the workplaces of people working on scaffoldings. The researches were carried out on 23 frame-type facade scaffoldings. The scaffoldings were examined from March to October 2017. Due to the specificity of works performed on scaffoldings, the researches were carried out in accordance with an individually adapted research program. The study analyzed the illuminance at particular points and variability in the lighting uniformity in a given workspace. Analysis of the obtained results showed a large variability in illuminance in workplaces of people working on scaffoldings. The measured illuminance levels in the workspaces on the one hand were higher than the minimum illuminance levels defined by the construction site standards, but on the other hand, illuminance levels that may dazzle the employees were also recorded. The luminous intensity depended on the season, time of day, location of the scaffolding, as well as the presence of a protective net installed on the scaffolding, which reduced the occurrence of values that could lead to situations in which the worker could be dazzled. The protective net installed on the scaffolding also reduces the differences in lighting in the scaffolding workspace, improving the lighting conditions of the workplaces.

In presented studies not significant effect of the illumination of blue sticky traps with red pulsating light on their effectiveness in the monitoring of the western flower thrips (Franklinie/la occidentalis Pergande) was found. Observed increase of the number of caught imagines on lighted blue sticky traps was not statistically significant in comparison to the control combination (blue sticky traps without any light).

The application of solid-state light sources in luminaires creates a new quality in illumination design works. In a confrontation with a commonly used but relatively unattractive flood method, the use of small-size luminaires allows one to present an illuminated architectural object in a more attractive way in the evening and at night. In this case, it is possible to apply the principles of illumination described in the literature, especially the principle of height amplification and the principle of depth amplification. The conceptual work of illumination with the use of a large number of small-size luminaires does not require the use of supporting graphical tools, but the specification of actual lighting equipment using only polygonal samples in this case is not possible. The paper presents selected issues of the key stages of the completed work. Using specialized computer software, a geometric model of the architectural object has been developed, facade materials have been parameterized, models of small-size illuminating equipment have been selected and, finally, calculations of luminance distribution on illuminated surfaces have been carried out. As a result of computer work, luminance distributions and photorealistic visualizations of illuminations from defined main directions of observation were obtained. The Lubomirski Palace in Przemysl is an example of the architectural object indicated for detailed works.

In the paper, an effective way to design asymmetrical optics for a uniform vertical surface illumination was presented. Assessment of the obtained distribution of luminance (illuminance) on the illuminated surface is done almost at the same time as designing the optical system elements. Advantage of the final application of the presented method in 3D will be independence from the implementation of time-consuming simulations in order to verify the already designed optics. Understanding the method and its application is simple and intuitive. Observing the luminance distribution, created on the illuminated surface almost at the same time as its design, allows to see the effect of adding the next elements of the optical system on this distribution.

The compositional graded quaternary barriers (GQBs) instead of ternary/conventional quantum barriers (QBs) have been used to numerically enhance the efficiency of AlGaN-based ultraviolet light-emitting diode (LED). The performance of LED with GQBs is examined through carrier concentrations, energy band diagrams, radiative recombination, electron and hole flux, internal quantum efficiency (IQE), and emission spectrum. As a function of the operating current density, a considerable reduction in efficiency droop is observed in the device with composition-graded quaternary barriers as compared to the conventional structure. The efficiency droop in case of a conventional LED is ~77% which decreased to ~33% in case of the proposed structure. Moreover, the concentration of electrons and holes across the active region in case of the proposed structure is increased to ~156% and ~44%, respectively.

This article is focused on considerations based on experimental studies concerning changes of selected parameters of identical compact fluorescent lamps (CFLs) intended for use in buildings during their operation. The studies constituted a long-term experiment whose goal was an evaluation of selected operating parameters of the CFLs in terms of meeting the requirements set out in the specified regulations as well as the issue of marking the lamps with the energy efficiency class. The measurements were performed with the authors’ experimental setup consisting of original equipment designed and made especially for the purpose of the measurements. The studies covered registration of the luminous flux as well as selected electrical parameters such as active power, current and the power factor during the so-called “start-up time” and operation time equal to 100 h, 500 h, 1000 h, 2000 h, etc. with a 1000 h step. The studies were finished with the moment of natural burnout of the CFLs tested. The results showed that the biggest drawback of CFLs is lack of preservation of the required time to reach 60% of the stabilized luminous flux just after short time of lamp operation. Similarly when assessing the conformity of the parameters declared by the manufacturer that have been verified, it can be stated that they are true only at the initial stage of lamp operation.

This article is focused on considerations based on experimental studies concerning changes of selected parameters of identical compact fluorescent lamps (CFLs) intended for use in buildings during their operation. The studies constituted a long-term experiment whose goal was an evaluation of selected operating parameters of the CFLs in terms of meeting the requirements set out in the specified regulations as well as the issue of marking the lamps with the energy efficiency class. The measurements were performed with the authors’ experimental setup consisting of original equipment designed and made especially for the purpose of the measurements. The studies covered registration of the luminous flux as well as selected electrical parameters such as active power, current and the power factor during the so-called “start-up time” and operation time equal to 100 h, 500 h, 1000 h, 2000 h, etc. with a 1000 h step. The studies were finished with the moment of natural burnout of the CFLs tested. The results showed that the biggest drawback of CFLs is lack of preservation of the required time to reach 60% of the stabilized luminous flux just after short time of lamp operation. Similarly when assessing the conformity of the parameters declared by the manufacturer that have been verified, it can be stated that they are true only at the initial stage of lamp operation.